Pressure sensors are normally applied to and set in the place where pressure change needs to be tested and responded, such as automobiles, aerospace, commerce, and other industries.
The sensing component, made by silicon MEMS (short for “Micro-electromechanical Systems”) technology, is the core of a pressure sensor. The encapsulation structure for sensing components has an important effect on the performance of pressure sensors. In the prior art technique, the encapsulation structure for sensing components which is applied in the medium like corrosive gas or liquid is shown in FIG. 1. First, silicon chip 107, the sensing component, which is processed by MEMS technology, is bonded to glass base 108, and the two are together adhered to the inner space of case 109. Second, wiring terminals 102 are sintered into the terminal holes of case 109 with glass powder 103. Then, weld the bonding pad of silicon chip 107 and one end of terminals 102 together with golden wire, and the other end of terminals 102 is welded to PCB 101. Fill the inner space of case 109 with silicon oil 105, and at last, weld corrugated diaphragm 106.
In case of this kind of encapsulation structure, once the corrosive medium contacts corrugated diaphragm 10, the pressure will transfer to silicon chip 107 through silicon oil 105 so as to prevent corrosion when the pressure is being transferred. However, as for this kind of encapsulation, the structure and manufacturing process is complicated and the cost is high. So it can't meet the needs of batch production and application of silicon pressure sensors.